Method for obtaining increased third dimensional viewing of objects from a traveling craft or vehicle



Dec. 10, 1940. 1 B BAR-row l 2,224,775

NCREA L VIEWING 0F OBJECTS FROM A TRAVELING CRAFT OR VEHICLE METHOD FOROBTAINING I SED THIRD DIMENSIONA Filed Oct. 28, 1938A Patented Dec. 10,1940 PATENT OFFICE METHOD lFOB OBTAINING INCBASED THIRD DIMENSIONALVIEWING F 0B- JEc'rs FlwM A VEHICLE I TRAAVELING CRAFT 0B' y John B.Bartow, Blue Bell, Pa., assignor to Bax-tow Beacons, Inc., Philadelphia,

of Pennsylvania Pa., a corporation Application October 28, 1938, SerialNo. 237,568

3 Claims. 'I'his invention relates to a novel method for obtainingincreased third dimension or relief efyfeet when viewing objects from atraveling craft or vehicle when the line ofQ travel of the craft or 6vehicle is disposed at an angle to the line' of vision between anobserver on the craft orvehicle and the objects.

, As is well known, the eyes are incapable of obtaining any substantialdegree of visual relief effect when viewing an object from a greatdistance. Generally speaking, good visual relief is obtained by the eyesup to a distance of about 500 feet from an object; but when the eyes areplaced at greater distances from the object, very little, if any, reliefeffect is obtained. For this reason, an object viewed by the eyes from agreat distance appears two-dimensional rather than` between the observerand said object. The invention is particularly useful to the pilot of anaircraft, for it enables him to obtain a threedimensional view of adistant object which would otherwise be visible only as atwo-dimensional oblect. Thus, the pilot of an aircraft traveling at ahigh altitude land in a direction other than directly toward a groundobject, may obtain a good three dimensional or relief view of saidobject. Of course, the invention is not limited to use by a pilot, butis usefulalso to other persons, such as passengers on the aircraft.

The invention achieves its object by causing the respective eyes ofanobserver on a traveling craft or vehicle whose line of travel is notdirect- 40 ly toward al distant object to be lviewed, to view saidobject alternately and successively at a frequency within thepersistence of vision of the human eye, the travel of the craft withrespect to the object causing the observers eyes to view the said objectalternately and successively from points ofY observation spaced asubstantial distance apart, so that the observer obtains athreedimensional view of the object. Thus, according to the invention,advantage is taken of the motion of the craft when traveling in adirection other than directly toward a distant object to be viewed, aswell as certain novel viewing means, to effect third-dimensional viewingof said object by the observers eyes from widely spaced points ofobservation. The means for eifecting yminiature motor is suillcient forthe purpose. If

third-dimensional viewing ofthe object preferably takes the form of anapertured opaque disk which is rotated'at a speed such that the'successive and alternate viewings/ bythe observers eyes take place at afrequency within the per- 5' sistence of vision, but the invention isnot thus limited as will be more clearly vseen later.

The invention may be clearly understood by reference to the accompanyingdrawing illustrating certain preferred forms thereof.

In the drawing:

Figures 1 and 2 are frontand side views, respectively, of a. portableapparatus constructed according to the invention. the views illustratingthe use of such apparatus by an observer;

Fig. 3 is a face view of anotherform of the apparatus, which, in thisinstance, is constructed Vas an integral part of a craft or vehicle;

Fig. 4 is a-detailed sectional view of the same apparatus; and

- Fig. 5 is an explanatory illustration by means of which the principlesof the invention may be more clearly understood.

Referring to Figs. 1 and 2, the portable device illustrated comprises apair of binoculars I, supported by the handle structure 2. Adjacent theouter ends of the eye-pieces, there is pro- 'vloed a rotatable opaquedisk lhaving an aperture 4 therein which is so located that it alignsalternately and successively with the eye-pieces as the disk is rotated.'The disk is rotatably supported by a hollow support 5 extending fromthe handle structure 2. A small motor (not visible) within the housingor'casing 6 serves as the motivating means for the disk, and the drivingconnection between the motor and disk may take the form of a exibleshaft extending'through the hollow support 5. This method of driving arotatable element is so well known that it is deemed unnecessary toillustrate the details thereof. ASince the disk is small, usually beingabout five inches in diameter, and it may be made of light material suchas aluminum, very little power is required to drive it, and, therefore,a

' desired, vthe motor may be energized by small dry cell batteriescarried within the handle structure 2.

'I'he disk l is rotated at a speed such that successive completeviewlngs of the object take place at a frequency within the persistenceof vision of the human eye, that is, 16 or more cycles per second. Nowwhen such a device is employed to view a distant object from a craft orvehicle which is traveling in a direction other than directly u towardsaid object, the travel of the craft serves, in conjunction with theviewing device, to greatly increase the third-dimensional effect.

Ihis maybereadilyseen byreferringtoFlg. 5' 5 wherein anobject to beviewed is indicated at O. Suppose that the two eyes of an observer viewthe object simultaneously from a position A--B about 500 feet from theobject, the points A and lB representing the respective eyes of theobserver. 0f course', the distance between the eyes as represented by Aand B is greatly exaggerated in relation to the distance from theobject, this being necessary for illustration within a small space. Theangle of vision is AOB. Now supl pose that thev observers eyes arepositioned at A.'B'` and again view the object simultaneously, thepoints A' and B' representing the eyes. According to the approximatescale of the ligure, the position A'- is about 2500 feet from the auobject. The angle of vision AOB! is much smaller than that'obtaining at500 feet and the thirddimension eii'ect or relief i.. quite poor. Ifitjwere possible, however, to separate the observers eyes so'as tolocate them at points A' and B" (which areon extensions of lines OA andOB respectively) the observe would obtain at 2500 feet the samethird-dimension effect as he would at 500 feet. since the angle A 'OB"is equal to the angle AOB, and the distance A'B" bear's the same relolation to AB'as the corresponding distances from the object bear toone'another.

Now suppose that the observer views the oblect with the device of -1 and2 from a craft or vehicle traveling in the direction ofthe broken $5line arrow, and thatv the rotating disk is revolving at a speed of 16 ormorerevolutions per second. Ifthespeedofthecraftissuchthatoneeye viewsthe object at points A' and the other veye views the object at point B",the effect is the o same as though the eyes were spaced apart thedistanceI A'B", giving the observer on the traveling craft or vehiclethe same third-dimension eifect as he would obtain at 500 feet with thenaked eyes viewing the object simultaneously. Thus the `third-dimensioneffect would be increased in the ratio between the distance A'B" and thedistance between the eyes.

Taking a more-specmc example, suppose that anv air-craft is traveling inthe direction of the wbrokenlinearrowofllgjataspeedof 180miles per hour,and that the disk 3 of the device of Figs. landzisrotatingataspeedof16revolutions per second before the eyes of an observer ontheaircraft.Fromthesegures,itmaybe readily calculated that'the aircraft will travelapproximately 16 feet during each revolution of the disk, and if theeye-pieces are 180" apart with respectfto thecenterofthedisk,asin1ll`gs. 1 and 2, the craft will travel-approximatelyeight feet o during the interval between successive vlewings of theobject by the two eyes. Now, since the distance between the eyes isapproximately two and one-half in ches, the third-dimensional viewing ofthe observer is increased by the invention k|15 in a ratioof'approximately 40 to 1. In other words, the invention obtains the samethirddimension -eifect that would be obtained if it were powble toseparate the observers eyes by a distance of approximately eight feetinstead of two and one-half inches. Since the alternate and, successiveviewings of the object take place at a frequency within the persistenceof vision, the observer obtains a good third-dimensonal view of theobject. 1I In Figs. 3 and 4, there is illustrated a further embodimentof the invention. wherein the viewing device is built into or formedintegral withl the craft or vehicle. In these figures. a wall ofthecraft is shown at 1, and is provided with an aperture large enough toaccommodates. disk l which may be approximately ve inches -in diameter,`as previously mentioned. The disk l is provided with an aperture l, andis mounted on a spindle Il rotatably carried by a plate Il. Theperipheral edge portion of plate Il is flanged, and is secured to wall 1about the aperture there-` in by means of fastening elements, such asrivets I2. The plate Il is provided with two apertures spaced apart thenormal distance between thev eyes, and adjacent. these apertures thereare mounted on the plate a pair of eye-'pieces I3. The disk 8 may bedriven by adexible shaft I4 actuated by a small motor (not shown).

When the disk l rotates, the opening l therein aligns successively withthe eye-.pieces I3, so 0 that an observer within the craft or vehicle,upon placing his eyes adjacent the outer ends of the eye-pieces. viewsadistant object ilrst with one eye and then with the other. 'I'herotation of the disk at a speed such thatcomplete viewings .of 88 theobject are obtained at a frequency within the persistence of vision,together with the travel of the craft, results in greatly increasedvisual relief, 'as above explained. Itis to be understood that the craftor vehicle is traveling in a direction other 'than directly toward theobject being viewed.

It will be noted that the eye-pieces I3 are only about90 apart withrespect to the center of the disk. For a given speed of the craft, thiswill 35' decrease the perspective, since obviously the craft will travela shorter distance between the successive viewings by the eyes.Consequently, it is preferred to have the eyes of the observer apartwith respect to the' center of the o If desired, more than oneopeningmay be provided in the disk, which will enable a reductioninthespeedofthedisk. Fbrexample,iftwo apertures are provided, the speedof the disk maybe reduced to 8 revolutions per second, since two 45complete viewings of the object will take place during each revolution.

In any case where an optical viewing system is employed, known means maybe employed to magnify the image thus enhancing the results ob- 50tained. 'lhus in the embodiments illustrated, the eye-pieces ma'y beequipped with lenses for this It will be apparent that the invention maybe practiced by using other forms of apparatus. For 55 example, shuttersmay be placed in front 4of the eyes ofthe observer and may be aperatedin a manner to effect alternate and successive viewings by the eyes at arate or frequency within the persistence of vision.

It will be understood, therefore, that the invention is not limited tothe specic forms illustrated, but is capable of further embodiments andmodiflcationsvwithin its scope.

I claim:

l. A method of obtaining increased third-y dimensional viewing of adistant object by an observer on a craft or vehicle proceeding on a lineof travel disposed at an angle to the line of vision ,m between saidobserver and said object, which consists in presenting alternately andsuccessively to the eyes of said observer views of the object at afrequency within the `persistence of vision of the human eyes, wherebydue to the travel of the craft the observers eyes view the objectsuccesu sively from points of observation spaced a distance apartsubstantially greater than the normal distance between the human eyes.

2. A method of obtaining increased thirddimensional viewing of a distantobject by an observer on a craft or vehicle proceeding on a line oftravel disposed at an angle to the line of vision between said observerand said object, which consists in rendering an object visiblealternately and successively to the eyes of said observer at a frequencywithin the persistence of vision of the human eyes, whereby due to thetravel of the craft the observers eyes view the object successively frompoints of observation spaced a distance apart substantially greater thanthe normal distance between the human eyes.

3. A method of obtaining increased thirddimensional viewing of a distantobject by an observer on a crai't or vehicle proceeding on a lineV oftravel disposed at an angle to the line of vision between said observerand said object, which consists in screening the eyes of said observerand unscreening said eyes alternately and successively at a frequencywithin the persistence of vision of the human eyes, whereby due to thetravel of the craft the observers eyes view the object successively frompoints of observation spaced a distance apart substantially greater thanthe normal distance between the human eyes.

JOHN B. BARTOW.

